diff --git a/diffphys-code-sol.ipynb b/diffphys-code-sol.ipynb
index ed96b32..3d738b2 100644
--- a/diffphys-code-sol.ipynb
+++ b/diffphys-code-sol.ipynb
@@ -173,7 +173,7 @@
    },
    "outputs": [],
    "source": [
-    "#!pip install --upgrade --quiet phiflow==2.2\n",
+    "!pip install --upgrade --quiet phiflow==2.2\n",
     "from phi.tf.flow import *\n",
     "import tensorflow as tf\n",
     "from tensorflow import keras\n",
@@ -1373,4 +1373,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 1
-}
\ No newline at end of file
+}